How severe is fault code C1115?

Serious — Stop or limit driving

OBD Code C1115: ABS Power Relay Output Short Circuit To Battery

Q: What does OBD code C1115 mean?

ABS Power Relay Output Short Circuit To Battery. The ABS system's power relay is stuck energized, continuously sending battery voltage when it should be off—like a light switch that won't turn off. This causes electrical stress and can drain the battery or damage the ABS control module.

Q: What are the symptoms of fault code C1115?

ABS warning light illuminated on dashboard, Battery drains quickly when vehicle is parked, ABS system non-functional or erratic braking behavior

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What This Actually Means

In plain language — no jargon

The ABS system's power relay is stuck energized, continuously sending battery voltage when it should be off—like a light switch that won't turn off. This causes electrical stress and can drain the battery or damage the ABS control module.

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Symptoms You May Notice

3 known symptoms for this code

ABS warning light illuminated on dashboard

Battery drains quickly when vehicle is parked

ABS system non-functional or erratic braking behavior

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ABS module monitors the relay output voltage to ground, expecting it to drop to near 0V when de-energized and rise to battery voltage when energized per system demand. A short to battery means the relay output remains at battery voltage continuously, regardless of module commands.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Relay Output Voltage (De-energized)	0.2-0.5V	10-14V (battery voltage)
Current Draw (Idle)	0.5-2A	>5A continuous

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

ABS Power Relay

Locate the relay in the engine bay fuse/relay box and swap with an identical unit to test; if fault clears, replace permanently.

2

Wiring harness to relay

Inspect relay connector pins and output wire for corrosion, melting, or pinched insulation causing a short.

3

ABS Control Module

If relay and wiring are clean, the module's internal output transistor may be shorted; requires module replacement or reprogramming.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code C1115 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.

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How to Clear Code C1115

What happens after you fix the fault

Once the fault is repaired, C1115 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When

Fault has been diagnosed and repaired
You want to confirm the repair worked
Code appeared after a sensor was cleaned

⚠️ Do Not Clear When

Preparing for an emissions/PUC test
Root cause is still undiagnosed
Check engine light is flashing

Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.